Magnetic mixer



Aug. 18, 1953 J. H. HAMMOND, JR

MAGNETIC MIXER 4 Shets-Sheet 1 Filed Nov. 19, 1949 m u mm J I I(Ittorneg Aug. 18, 1953 J. H. HAMMOND, JR 2,649,288

MAGNETIC MIXER Filed Nov. 19, 1949 4 Sheets-Sheet 2 IIIIIIIIIIIIIIIIIII"0 O "IIIIIIIIIIIIIIIIII/ v I 5 ISnventor JOHN HAYS HAMMOND JR.

Gttorneg Aug. 18, 1953 J D, JR 2,649,288

I MAGNETIC MIXER Filed Nov. 19, 1949 4 Sheets-Sheet 3 3 nventor O F l 3JOHN HAYS HAMMOND,JR.

Gttorneg Patented Aug. 18, 1953 UNITED STATES @ATENT GFFii'IE MAGNETICMIXER John Hays Hammond, Jr., Gloucester, Mass.

Application November 19, 1949, Serial No. 128,337

1 Claim. 1

This invention relates to mixing machines for soda fountains and moreparticularly to mixing machines in which the container for the materialto be mixed is held in position by means of magnetic attraction.

More specifically the invention provides a mixing machine which isprovided with an annular magnet afilxed to the machine and an annularring of ferrous material attached to the container, which is held inoperative position by means of the magnetic attraction between themagnet and the ring.

I'he invention also provides means for normally holding the stirringshaft in a raised position and then lowering it into an operativeposition when the machine starts to function.

The invention further provides means for automatically starting themotor when the container is placed in the operative position.

The invention also provides means for guiding the container into theproper position when it is placed in the machine.

Ihe invention also consists in certain new and original features ofconstruction and combinations of parts hereinafter set forth andclaimed.

The nature of the invention, as to its objects and advantages, the modeof its operation and the manner of its organization, may be betterunderstood by referring to the following description, taken inconnection with the accompanying drawings forming a part thereof, inwhich Fig. 1 is a side elevation partly in section of a magnetic mixerconstructed in accordance with the invention, showing the parts in theinoperative condition,

Fig. 2 is a bottom plan view of the mixer taken on line 2".. of Fig. 1.

Fig. 3 is side elevation similar to Fig. 1 showing the mixer providedwith a container and in operative position,

Fig. 4 is a top plan View of the container shown in Fig. 3.

Fig. 5 is a fragmentary side elevation, partly in section, of a modifiedform of magnetic mixer, and

Fig. 6 is a section taken on the line 6-6 of Fig. 5.

Like reference characters denote like parts in the several figures ofthe drawing.

In the following description parts will be identified by specific namesfor convenience, but they are intended to be generic in theirapplication to similar parts.

Referring to the form of the invention shown in the accompanyingdrawings and more particularly to Figs. 1 and 2 a mixing machine H isprovided with a base I2 and an upright pedestal I3. Attached to theupper end of the pedestal I3 is a motor I4. Secured to the lower face ofthe motor I4 is a circular plate I 5, which is made of any suitablenon-magnetic material, such as brass or aluminum. Located between theplate I5 and the motor I i are spacers I6.

Surrounding the circular plate I5 and secured thereto is a cone shapedguide H which is provided with a large notch I8 on the part facing thepedestal I3. Located in the notch I 8 and secured to the pedestal I3 isa cylindrically shaped vertical guide I9.

Mounted on the under surface of the circular plate I5 is an annularshaped permanent magnet 2I which is notched as shown at 22 and 23. Themagnet 2! is so magnetized that north and south poles are produced atthe points indicated by the letters N and S. If so desired the annularmagnet 2| may be divided into a plurality of short sections each havingits own north and south poles.

Pivotally mounted in the pedestal i3 is a contact arm 25, one end ofwhich is provided with a curved finger 26 which extends through holes 27and 28 in the plate I5 and magnet 2| respectively. Normally the arm 25is held in the position shown in Fig. l by means of a light tensionspring 29. In this position the finger 26 projects slightly below thelower surface of the magnet 2 I. Mounted on but insulated from the arm25 is a contact plate '3! which at suitable times engages two fixedcontacts 32 and 33 which are connected in an electric circuit 36, whichis connected to a suitable source of electricity 35 and to the windingof the motor 54, so that when the con tact plate 3| engages the contacts32 and 33, the motor I4 will operate.

If so desired the contact arm 25 could similarly control a circuit fromthe source 35 to an electromagnet which could replace the permanentmagnet 2| thus providing a stronger electric field.

The electric motor I4 is provided with a shaft 3'! which rotates insuitable bearings not shown and upon which is mounted the armature ofthe motor, which is preferably of the universal series wound type. Endplates 32 are secured to the motor frame to hold the shaft 31' inposition. The shaft 31' is provided with two concentric holes 43 and 44of different diameters each extending approximately half way through theshaft.

Mounted in the shaft 3! and projecting into the hole 44 is a pin 45,which engages a spiral groove 46 provided in a rod 41 which is slidablyand rotatably mounted in the hole 44. Wound around the rod 4! is acompression spring 48 the upper end of which is attached to the rod 4!and the lower end to the shaft 31. A cap 49 is mounted on the top of therod 4! and fits into the hole 43 in the shaft .i'l. The rod 41 projectsdownward through a hole 5! in the plate l5 and at its lower end isprovided with vanes 52, mixing disc 53 and a propeller 54 which ispitched to exert a downward thrust on the rod 41 due to its rotation inthe liquid in the container.

Referring to Figs. 3 and 4, a container 55 is shown which consists of anelongated cone shaped portion 55 to the top of which is attached a ring5? of ferrous metal of the approximate size of the annular magnet 2 I.

Operation of Figs. 1-4

In the operation of the magnetic mixer depicted in Figs. 1-4, theingredients which it is desired to mix are placed in the container 55,which is then placed in the position shown in Fig. 3. In placing thecontainer in position it will be guided to the proper location by meansof the conical guide H and the cylindrical guide 19. The containe 55will be held in this position against the force of gravity by means ofthe magnetic attraction between the annular magnet 2| and theferrousmetal ring 5'! which is in contact therewith.

When the container is placed in position the ring 51 will engage thefinger 26 of the contact arm 25, which will be rotated in a clock-wisedirection from the position shown in Fig. 1 to that shown in Fig. 3.This motion will cause the contact segment 3| to engage the fixedcontacts 32 and 3-3, thus closing the circuit from the power supply 35to the motor M, which will start rotating in a counter-clockwisedirection as indicated by the arrow in Fig. 2.

When the motor starts to rotate the parts will be in the position shownin Fig. 1. As the shaft 5? starts to rotate it will tend to carry therod 4'! with it in the same direction. Due, however, to the inertia ofthe rod 4'! and the resistance caused by the vanes 52 and discs 53 inthe material to be mixed, the rod 41 will tend to hold back and not torotate as fast as the shaft 31.

This will result in a relative rotation between the shaft 37 and the rod41 causing the pin 45 to move in the spiral groove 46 with the resultthat the rod 55 is moved down into the material to be mixed against theforce of the spring 43, which at the same time is wound tighter aboutthe rod t! due to the relative rotation between the shaft 31 and the rod41. When the pin 45 reaches the top end of the groove 4-6 the shaft 31and the rod ll will be locked together and both will ro tate at the samespeed.

After the mixing discs 53 have mixed the ingredients sufiiciently thecontainer 55 is removed from the machine I i manually. When this occursthe pressure of the ring 5'! on the finger 25 will be released allowingthe contact arm 25 to rotate in a counter-clockwise direction under theaction of the spring 29 from the position shown in Fig. 3 to that shownin Fig. 1. This in turn will break the circuit to the motor M causing itto stop.

As soon as the shaft 31 has come to a stop the spring 48 will tend topull the rod 41 up and at the same time will tend to unwind. Thecombination of these two actions will cause the rod ll to rotate in acounter-clockwise direction, as seen in Fig. 2, and to move up, thuscausing the pin 55 to slide in the spiral groove 46 from th positionshown in Fig. 3 to that shown in Fig. 1.

The entire mechanism will now be in the position shown in Fig. 1 whereit will remain until the container 55 is again placed in position, atwhich time the cycle of operations will be repeated.

Of course either the propeller 54 or the pin 45 and spiral groove it maybe used independently if desired. In either case when the motor I4 stopsthe spring as will return the rod 4's to its initial position.

Referring to the modified form of the invention shown in Figs. 5 and 6,the mixer 5! is of the same general construction as that shown in Figs.1 and 2 up to and including the electrical circuit 3 5. The motor it isprovided with a shaft 52 having a longitudinal hole 53 therein. Endplates '64 are secured to the motor frame to hold the shaft 52 inposition. Slidably mounted in the hole :53 is a rod 55 made ofnon-magnetic material, which is provided with a longitudinal hole :56the upper end of which is threaded as at 65. The rod 65 is also providedwith two longitudinal slots El. A pin 68 is provided which is secured inthe shaft 62 and passes thru the slots til, thus allowing the rod tomove up and down in the shaft 62, but preventing it from rotating withrespect thereto. A cylindrical plug 69 is mounted in the hole 66 and isheld against the pin '58 by means of a compression spring H. A core T12of magnetic material, such as soft iron, is provided with a threaded end13 which is screwed into the threaded portion til of the rod 55 andholds the spring ll in position.

Mounted on top of the motor I4 is a solenoid 15 having a laminated ironframe it and a winding H, which surrounds the rods 55 and 12. The frameit is provided with clearance holes 18 thru which the rods 65 and 12pass. A thin sheet metal cover is is provided which encases the motor [4and the solenoid l5.

One side of the winding ll of the solenoid i5 is connected by aconductor 8| to one side of a resistor 82 the other side of which isconnected to a contact 83, which at suitable times engages the contactplate 31. A switch 85 is connected across the resistor 82, which may beused for short circuiting said resistor, when the solenoid "i5 isoperated on A. C. The other side of the winding ll of the solenoid "i5is connected by a conductor 85 to the return conductor of the circuit34.

Operation of Figs. 5 and 6 In the operation of the modified form of theinvention depicted in Figs. 5 and 6, the container 55 is placed inposition in a manner similar to that described in connection with Figs.1-4. This will cause the arm 25 to be rotated in a clockwise directioncausing the contact segment 3! to engage the three contacts 52, 33 and83.

This action will start the motor l4 rotating and at the same time willenergize the solenoid 75 which will cause the iron core 12 to be pulleddown into the solenoid 15. As the core 12 is attached to the rod 65 thelatter will also be moved down against the action of the spring ll whichis compressed between the core 12 and the plug It is thus seen that assoon as the motor [4 starts the rod 65 will rotate due to the pin 68 inthe slots 51 and at the same time it will be moved down into theingredients in the container 55 which are thoroughly mixed due to theaction of the mixing vanes 53.

This action will continue until the container 55 is removed thusallowing the arm 25 to return d to the position shown in Fig. 5 underthe action of the spring 29. This will break the circuits to the motorl4 and the solenoid 15, thus causing the motor [4 to stop the rotationof the rod 65.

When the solenoid 75 is deenergized the core '12 will no longer be heldin the down position, but will be moved upward together with the rod 65under the action of the spring 1| until the parts have assumed theirinitial positions as shown in Fig. 5. The mixer will then remain in thiscondition until it is ready to be used again.

If the mixer is to be used with D. C. supply, it will be necessary toopen the switch 84 thus throwing the resistance 82 in series with thesolenoid winding 11.

Although only a few of the various forms in which this invention may beembodied have been shown herein, it is to be understood that theinvention is not limited to any specific construction but may beembodied in various forms without departing from the spirit of theinvention.

What is claimed is:

A mixing device comprising a container, a support to hold said containerin position for stirring, a motor mounted on said support and having ahollow vertical shaft, a, stirring rod mounted in said shaft to bedriven thereby and sliding axially between retracted and stirringpositions, spring means normally holding said rod in retracted position,.a solenoid having a core attached to said rod and positioned to advancesaid rod downwardly when energized and circuit means including acontainer actuated switch to energize said solenoid.

JOHN HAYS HAMMOND, JR.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,412,401 Godfredsen Apr. 11, 1922 20 1,431,715 Wolters Oct.10, 1922 1,711,396 Ruetz Apr. 30, 1929 2,051,883 Morgan Aug. 25, 1936

